This invention relates to a curved section and guide assembly for a scraper-chain conveyor.
In order to direct the scraper assembly of a scraper-chain conveyor around a curve in as friction-free a manner as possible, it is known to use an assembly having a curved conveyor section and guide means constituted by two vertically spaced, independently rotatable pulley wheels. The scraper or the chain of the scraper assembly bear radially against the upper pulley wheel when in the upper (conveying) run, and bear radially against the lower pulley wheel when in the lower (return) run. In operation, the pulley wheels are rotated by their interaction with the scrapers (or by their interaction with the drive chain of the scraper assembly), and they conduct the scraper assembly around the curve with only low friction losses.
In this type of assembly, the vertical axle which carries the pulley wheels is held between an upper, cover plate and a base plate of a housing which accommodates the pulley wheels. The base plate and the cover plate are fixed to the inner curved wall of the curved conveyor section. Since the pulley wheels penetrate the inner curved wall of the curved conveyor section (to enable them to contact the scraper assembly), the cover plate is connected to said inner wall only at the ends of the curved conveyor section. This is to be contrasted with the base plate which is connected to said inner wall along the entire length of the latter. The floor panel of the curved conveyor section (which separates the two runs of the scraper assembly) extends through the pulley wheel housing, and is bolted to the base plate and the cover plate at the edge of the housing remote from the curved conveyor section.
This type of assembly has a number of disadvantages. In particular, the fitting and removal of the pulley wheels are difficult and time-consuming. For example, during removal, the vertical axle must first be withdrawn upwardly from the housing. Then, the pulley wheels have to be extracted radially, which can only be done once the bolted connection of the floor panel to the cover plate and the base plate is released. When anti-friction bearings are used for rotatably mounting the pulley wheel on the axle, fitting and removal are rendered considerably more difficult because the inner and outer races of the anti-friction bearings are difficult to put together and withdraw, particularly in the enclosed position between the base plate and the cover plate. A further disadvantage is that the pulley wheel housing is expensive to make, leads to considerable production costs, and makes handling and transport in mine roadways and galleries difficult.
The aim of the invention is to produce a curved section and guide assembly which enables the pulley wheels to be fitted and removed more easily and quicker.